The present invention concerns index searching systems and particularly abstracting techniques for use in conjunction with such systems. In a typical case, an index search system incorporates a central processor or control unit having input means for entering information from storage media, such as magnetic record cards, a keyboard means for indicating to the system "inquiries" indicative of information required from the index and printing means serving as an output to provide the user of the system with information that is located corresponding to the inquiries put in the system.
A number of references of interest in the present case have been indicated above. These include the Locklar and Sims patents that illustrate systems utilizing magnetic tape record media for recording and reproducing information in conjunction with printing means. The principles of the present invention are equally applicable to tape systems. The Palmer and Becker references are illustrative of th IBM "Selectric" Typewriter printing mechanisms. Such printing mechanisms make use of a single element printing head with means for rotating and tilting the head in order to effect character selection during printing.
The Kolpek U.S. Pat. No. 3,674,125 describes a system making use of magnetic record cards for recording and reproducing information in conjunction with a printer, such as the single element printer just described. The Andrews case describes pack-feeding mechanisms for feeding a plurality of magnetic record cards at high speeds into a system for recording and reproducing information as may be required and such a pack-feed mechanism may be useful in the present system for inputting information into the system for use as an index.
The Montgomery patent relates to a system for abstracting information by utilizing an alphabetical character to designate the fact that a word falls within a predetermined group of words. This system classifies documents according to words which fall in the categories. However, the Montgomery system has no provision for recording key words of indefinite number describing an article on a search track and automatically abstracting the words comprising a search record by utilizing predetermined characters of each such words to provide information to group counters, the groups corresponding to groups of alphabetical characters having near equal distribution patterns.
The various customer engineering manuals are useful supplements in providing additional information concerning the IBM "Selectric" printer in its various forms. The IBM "Selectric" composer manual describes a processor having a magnetic tape as an input and incorporating a number of registers, accumulator circuits, various memories, address registers, and decode circuits that are comparable to circuits used in the system of the present case.